WASHINGTON (Florida Today) -- NASA's administrator tried to reassure wary lawmakers Thursday that
his agency isn't foot-dragging on a rocket to take astronauts into deep
space by the next decade.

"We need a 70
metric-ton vehicle, and we are on schedule, on target and on cost to
provide that 70 metric-ton vehicle," Charles F. Bolden Jr. told members
of the Senate Appropriations subcommittee that oversees NASA funding.

NASA
is asking for $17.7 billion for fiscal 2014, which begins Oct. 1. That
includes $2.73 billion to develop the Space Launch System (SLS)
consisting of an Orion multi-purpose crew vehicle and the deep-space,
"heavy-lift" rocket that will carry it first to an asteroid as early as
2021 and then to Mars by the 2030s.

The
top Republican on the panel, Richard Shelby of Alabama, raised concerns
that the amount NASA wants for SLS is some $200 million less than the
agency received in fiscal 2012.

He
questioned whether the proposed reduction is linked to the $300 million
increase NASA is seeking for the Commercial Crew Program to help
private companies develop a spacecraft to carry astronauts to the
International Space Station.

But
Bolden said SLS remains one of the agency's top three priorities, along
with development of the James Webb Space Telescope and the Commercial
Crew Program.

The NASA administrator told senators that work on the deep-space mission is well underway.

He
said the launch complex at Kennedy Space Center in Florida has been
significantly upgraded, J-2X engines have been successfully tested at
Stennis Space Center in Mississippi, and a major engine component has
been tested at Marshall Space Flight Center in Alabama.

"We are confident that we can carry out his program with the budget that we had requested," he said.

Thursday's
exchange reflected the tension between Congress and the administration
over the direction of the space program in recent years, especially when
budgets have grown tighter.

The
concerns Shelby aired Thursday are similar to those lawmakers raised
Wednesday at a House Science, Space and Technology Committee hearing.
Committee Chairman Lamar Smith, R-Texas, said at that hearing he's
"disheartened" by what he sees as NASA's "ever-changing goals."

Many
lawmakers, especially Republicans, remain unhappy with President Barack
Obama's decision in 2009 to scrap the Constellation program to return
to the moon.

They now support NASA's planned missions to asteroids and Mars, but are far less enthusiastic about the Commercial Crew Program.

NASA
says that's because the program has never been fully funded. The $525
million initially approved for the program in fiscal 2013 was well short
of the $801 million the administration had requested.

The
White House is seeking $821 million for the program in fiscal 2014,
which Bolden said would keep it from falling further behind schedule.

Otherwise, NASA will have to keep paying Russia $63 million every time it sends an American astronaut to the space station.